PIGMENTSBY Dr Hasan AskariPATHOLOGY DEPARTMENT

PIGMENTS

Pigments are colored substance.

It may be exogenous & endogenous.

Exogenous coming from outside the body.

Endogenous synthesized within the body.

EXOGENOUS PIGMENTS

Carbon (coal dust),air pollutant & tattooing. Mechanism: Inhaled macrophages (alveoli) transported to

lymph node (tracheobronchial region). Black color of lungs (anthracosis) & lymph node. In coal miners carbon dust induce fibroblastic

reaction or emphysema coal worker’s pneumoconiosis.

Tattooing phagocytosis by dermal macrophages.

EXOGENOUS PIGMENTS

EXOGENOUS PIGMENTS

TATTOOS

TATTOO

EXOGENOUS PIGMENTS

ENDOGENOUS PIGMENTS

Lipofuscin (lipochrome or wear & tear pigment) Melanin Hemosiderin

ENDOGENOUS PIGMENTS

ENDOGENOUS PIGMENTSPIGMENTS

LIPOFUSCIN: • It is insoluble polymer of lipid & phospholipid with

protein by lipid peroxidation.• Yellow-brown color.• Not harmful.• It shows sign of free radical injury & lipid

peroxidation.• Mostly in liver & heart of aging, malnutrition &

cancer cachexia.

ENDOGENOUS PIGMENTSPIGMENTS

MELANIN:• It is endogenous , non-hemoglobin derived black –

brown pigment.• In melanocytes enzyme tyrosinase catalyze the

oxidation of tyrosine to dihydroxyphenylamine.• OCHRONOSIS: (Homogentisic acid)- Occur in patient with alkaptouria (metabolic

disorder)- Black pigment deposide in skin, connective tissue &

cartilage.

ENDOGENOUS PIGMENTS

EENDOGENOUS PIGMENTSNDOGENOUS PIGMENTS

HEMOSIDERIN:• Storage form of iron hemoglobin derived golden-

brown granular or crystalline pigment.• Iron transported by transferin stored in cell by

apoferrin form ferritin excess iron excess ferritin form hemosidrin granules.

• Normally seen in mononuclear phagocytes.• E.g: bruises

BRUISE

Just chill